Is a Mazda Rotary-Fed Volt Fighter On Its Way?

It looks like the Chevy Volt will soon have some more competition on its way from an initially Japanese market range-extended electric car from Mazda, and it will be rotary-based.

According to Autocar, Mazda CEO Takashi Yamanouchi confirmed during a speech in Moscow that the company is still committed to the rotary engine and it will come back next year in Mazda’s new take on something akin to GM’s Volt/Ampera.

The rotary engine has been the subject of many research projects at Mazda since its introduction more than 40 years ago. Hydrogen-powered versions (pictured) have been developed, as well as test mules for it to run on all kinds or renewable energy.

“When I joined the company in 1967, it was the rotary engine that motivated my decision,” Yamanouchi said. “We continue to explore ways to improve the fuel efficiency and capabilities of the rotary engine so it can be the primary power source of a car again.”

Mazda recently tested an electric version of its Mazda5 minivan that used a hydrogen-fueled rotary engine as a range-extending generator. No word yet from Yamanouchi as to what the vehicle’s purpose, size or layout would be.

The company is getting ready to launch in Moscow the new generation of its Mazda6 sedan and it would not be a stretch to imagine this new sedan fitted with the electric motor plus rotary range extender combination as a response to Toyota’s popular Camry Hybrid.

Yamanouchi did say it will only be leased in Japan initially.

The benefits of using the rotary engine as a generator are huge. First, the rotary engine is a very light assembly, which allows for interesting weight gains when compared to a conventional inline-four cylinder unit; vibrations and harshness are also greatly reduced.

The major drawbacks of a rotary come from accelerating and decelerating, causing rapid wear and consumption issues. Using the rotary as a generator allows the rotary to stay close to its ideal 2,000 rpm, preventing the wear and consumption issues.

Long known as an ardent proponent of the rotary engine, Yamanouchi has also been quoted many times as saying research on this unique type of engine will continue at Mazda for as long as he is around.


  • John D.

    The rotary engine has been great, except for that tip seal issue. When you look at the picture, it jumps out at you. Those seals have a much longer distance to travel then the old fashion piston ring. As much as the engine tickles my interest as a fascinating design, seeing those same old tip seals that drove Mazda to the point of dropping the engine from their convention vehicles, gives me pause from a purchasing standpoint. Still, listening to the engine run is downright dreamy!

  • MrEnergyCzar

    @John D. Thanks for the advanced insight into the rotary seal design…


  • tgordi

    The best engine sound I know of is that of our Nissan Leaf. When you push the gas pedal, the car jumps with a Batmobile sound. And I love it!

  • Kurth

    High thermal efficiency is what I am waiting for, Prius is going to break 40% soon with their atkinson cycle engine, and is mated with a very low CD. Mazda is my favorite car company, so I am looking forward to see what they will come up with.

  • John D.

    I think they (Prius / Atkinson) are at 34% now, so adding 6% is not science fiction. What a change from the expected norm of 15% (Otto) a few years back! Still, I like the idea that every design concept (just about) is on the table! May the best one win!

  • Jim Larsen

    Diesels already get over 50%. There isn’t much value in an Atkinson engine when compared to that.

  • Jim Larsen

    Diesels already get over 50%. There isn’t much value in an Atkinson engine when compared to that.

  • No more carcinogenic diesels

    Jim Larsen: Only in your dreams. Diesel engines found in the passenger cars never get over 50% thermal efficiency, more like 30-35% at best.
    However 50% can be achieved in big ship engines but those have nothing to do with car engines.
    Atkinson cycle engines in hybrid powertrain have given the best efficiency so far, diesels are behind them and much more polluting.

  • Van

    I had the pleasure of driving a rotary engine sports car, smooth as silk.
    But as John D alluded to, it used oil.

    I think thermal efficiency is a good indicator for choosing which engine to buy, but without a reliable information source, we get numbers for various engines from 15% to over 50%.

    As a rule of thumb, most of us accept that Diesel engines are more efficient than gasoline engines, so expect 28% to 38% thermal efficiency for gas and 38% to 43% for diesel car engines. For example a Jetta TDI diesel gets 41% versus the Prius at 37%.

  • John D.

    The most efficient Diesel engines are actually found in locomotives. We think of them as big heavy beasts, but what is going on is really cool. They are two stroke supercharged diesels that operate at one specific RPM. The intake compressor keeps the manifold at a significant pressure (air only.) Each cylinder only has exhaust valves. At the bottom of the “Power” stroke, a slot at the bottom of the cylinder is uncovered allowing the pressurized air to enter. At the same time, the exhaust valves open. This purges the cylinder while burning off any unburnt fuel elements. (No catalytic needed!) The valves close and the air is compressed. Near TDC, the fuel is injected and the power stroke begins again. Half the cycles = half the friction. Power is controlled by the quantity of fuel injected. This engine turns a generator, which runs an inverter/chopper that drives the traction motors on the wheels. There are technical issues regarding downsizing the design, and locomotive engines have a horrible start-up until manifold pressure is attained. Still, with a little work, I think it is something we may someday see adopted.

  • Al Bunzel

    Why is Mazda waiting to produce their EV with range extender? If they really wanted to have a range extender, couldn’t they use an existing engine they already produce?

    In my opinion, it is just another stall tactic so that they can say they are working on an EV, but it is still under development because the gas motor is still be “developed”.

  • Van

    I think the little fish are waiting for the big fish to develop the next generation battery, i.e 400 Wh/kg at a cost of $125/kwh. Then as the song goes they will swim and swim all over the dam. :)